Using the method of canonical group quantization, we construct the angular momentum operators associated to configuration spaces with the topology of (i) a sphere and (ii) a projective plane. In the first case, the angular momentum operators derived this way are the quantum version of Poincaré's vector, i.e., the physically correct angular momentum operators for an electron coupled to the field of a magnetic monopole. In the second case, the operators one obtains represent the angular momentum operators of a system of two indistinguishable spin zero quantum particles in three spatial dimensions. The relevance of the proposed formalism for the progress in our understanding of the spin–statistics connection in nonrelativistic quantum mechanics is discussed. Introduction The connection between the spin of quantum particles and the statistics they obey is a remarkable example of a simply stated physical fact without the recognition of which many physical phenomena (ranging from the stability of matter and the electronic configuration of atoms to Bose–Einstein condensation and superconductivity) would not have an explanation. Nevertheless, the simplicity of the assertion “integer spin particles obey Bose statistics, and half-integer spin particles obey Fermi statistics” stands in bold contrast to its intricate physical origin. Indeed, Pauli's proof of the spin–statistics theorem [Pau40] (improving on earlier work by Fierz [Fie39]), showed that the spin–statistics connection was deeply rooted in relativistic quantum field theory. The path to a rigorous proof of this theorem (from the mathematical point of view) was a long one and involved the efforts of many people (see, e.g., the book by Duck and Sudarshan [DS98b]).
We review the formulation of quantum mechanics for identical spinning particles with wavefunctions that are singlevalued when permuted configurations are identified. The identification requires the spins to be smoothly permuted along with position variables, so spin is represented in a position-dependent ‘transported basis’, rather than the usual fixed basis. The simplest transported basis, constructed in terms of spins represented as pairs of commuting harmonic oscillators, gives the correct connection between spin and statistics. More complicated constructions can give the wrong exchange sign. The theory is generalized to incorporate additional properties such as isospin, color and strangeness. Some remarks about the relation between this approach and those based on relatitivity and/or field theory are given.
Abstract We demonstrate that the spin-statistics connection -- fermions carry half-integer spin and obey Fermi-Dirac statistics, bosons carry integer spin and obey Bose-Einstein statistics -- emerges as a topological theorem within the Hopf soliton framework, requiring no independent axiom. The configuration space of a single Hopf soliton with charge
H=0 is the mapping space
Q=MapsH(S3,S2), whose fundamental group
π1(Q)=Z2 renders
2π rotation topologically non-trivial. The Finkelstein-Rubinstein construction then selects the double-valued (fermionic) quantization: wavefunctions on
Q acquire a sign under
2π rotation, yielding spin-1/2. Exchange of two identical
H=0 solitons is topologically equivalent to
2π rotation of one, enforcing antisymmetric wavefunctions -- the Pauli exclusion principle derived from topology. The photon (
H=0) has simply connected configuration space (
π1=0), automatically giving integer spin and Bose-Einstein statistics. In 2+1 dimensions, the fundamental group becomes
Z (the braid group), producing anyonic statistics. The geometric (Berry) phase under adiabatic rotation reproduces the FR sign rule exactly. We compare this topological proof with the Streater-Wightman axiomatic proof and identify the structural reasons for their agreement. Keywords: spin-statistics theorem, Finkelstein-Rubinstein quantization, Hopf soliton, configuration space topology, fundamental group, Pauli exclusion principle, anyons, Berry phase, braid group, topological quantum field theory Keywords physics spin statistics fermion boson topology soliton hopf finkelstein rubinstein Type Preprint License CC BY 4.0 Date 2026-03-26 Subject Theoretical Physics DOI 10.5281/zenodo.19163319 © 2026 Alexander Novickis. Licensed under Creative Commons Attribution 4.0 International.